How to protect the world's largest living thing? Build it a border wall

Pando, the world's largest living thing, is dying. But conservationists have found an unexpected way to protect it.

Pando is a clonal colony of a single male quaking aspen that has been genetically confirmed to be a massive single organism connected at the roots.
(Photo: J Zapell/Wiki Commons)

Walking through this aspen grove in Utah, you could be forgiven for mistaking the forest for the trees. That's because this is not really a grove of separate aspen trunks at all, but rather a single living organism — a single root system spread over 43 hectares in Utah — that is the most massive living thing in the world, reports New Scientist.

It has been named Pando, and scientists believe it may be anywhere from 2,000 to 1 million years old. But sadly, this magnificent organism is dying. An influx of hungry deer and cattle, which eat Pando's young stems, is playing a large part in its demise, but climate change-induced drought, insects and disease aren't helping either.

“It’s falling apart on our watch,” bemoaned Paul Rogers of Utah State University. “The old trees are dying, and the young ones are being eaten.”

But Rogers and his colleagues aren't content to stand idly by. They are testing out a simple and unexpected but, so far, effective conservation plan, by building a border fence around a 7-hectare section of the grove.

Rogers' plan also involved attempting to stimulate tree growth by burning vegetation, clearing juniper bushes growing among the trees, and cutting mature aspens, methods that have been shown to promote new sprouts in the past. But it was the border wall that has proven to be the single most effective way to protect Pando. After three years, the part of Pando inside the fence contained more than eight times as many stems per hectare as an unfenced area.

“It was a neat surprise that we can get pretty good results with fencing alone,” Rogers said.

The reason fencing is so effective is that it keeps out grazing animals, the most damaging of which are introduced cattle. Even so, it's unclear whether fencing off the whole of Pando's area is a practical option. It's a huge area to wall off, and walls can negatively effect the natural ecosystem around Pando that's also important for its long-term health. Still, the effectiveness of this experimental border fence at least showcases the threat most immediately dangerous to Pando: invasive or overpopulated grazers.

Pando's long-term survival still depends on managing a number of other threats, but at least for now, there's hope for this ancient life form.